AERCO Electronic Controls System (ECS) - Manual (Page 42)

Electronic Control System (ECS) and Type CXT-E Valve
7. TROUBLESHOOTING
Page 42 of 82
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, New York 10913 • Phone: 800-526-0288 VD2: 02/28/14
OMM-0003_0D AC-105
Table 7-1. Troubleshooting – Control Valve CXT-E
NO.
FAULT
INDICATION
PROBABLE CAUSE CORRECTIVE ACTION
T1
System not
operating.
Control Valve is
closed and
outlet water
temp. is far
below setpoint.
1. No power supplied
to Control Valve
2. Control signal not
being supplied from
Temp. Controller.
1. Disconnect Valve Actuator plug and
verify that 24 VDC power is present at
pin 2 of Actuator cable. Restore power if
necessary. If System includes ECS,
proceed to Table 7-2 and check Over-
Temp Switch to ensure it has not
tripped.
2. Verify presence of 4 - 20 mA control
signal at pin 3 of Actuator cable. If
control signal is not present,
troubleshoot ECS per Table 7-2.
T2
System over-
heats by more
than 10°F above
the desired
setpoint.
Outlet temp is
below Over-
Temp limit setting
CAUTION!
Over-tightening
the Pack-ing nut
may trap the
Valve Stem and
slow or stop
Valve motion.
1. Control Valve not
fully closed.
2. Temp. Controller not
set properly or
defective.
3. Valve Actuator not
properly secured to
Linkage Assembly.
4. Foreign matter in
Valve Seat
1. Check the 4 – 20 mA control signal
being supplied to Actuator. If signal is
greater than 4 mA when heater outlet
temperature is 10°F (or more) above the
desired setpoint, proceed to next item in
list.
2. Refer to Section 3 – ADJUSTMENTS
and check current setting of Temp.
Controller. Readjust if necessary. If
adjustment does not clear fault, proceed
to Table 7-2 and continue.
3. Check Actuator U-bolt securing it to
Linkage Assembly. Tighten if needed
and readjust the CXT-E Control Valve
per Section 3.
4. If Valve still does not close after
checking the above items, disassemble
the Valve and clean the Seat per steps
CM18 – CM28 in Section 8.
T3
System outlet
water
temperature is
below desired
setpoint
CAUTION!
Over-tightening
the Packing nut
may trap the
Valve Stem and
slow or stop
Valve motion.
1. Temp. Controller not
properly set
2. Control Valve not
opening properly.
1. Refer to Section 3 –ADJUSTMENTS.
Check the current ECS Temp.
Controller setting. If the setting is below
the desired setpoint, readjust as
necessary.
2. Check as follows:
•
Ensure Actuator is secured to Linkage
Assembly. Tighten if needed.
•
Verify that 24 VDC power and 4 – 20
mA control signal are present at
Actuator pins 2 and 3 respectively.
•
To ensure Valve is not binding, check
Seal Retainer per steps CM1-CM10 of
Section 8 Corrective Maintenance.
Replace items as necessary.